The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
U.S. Pat. No. 3,385,512 A discloses a bladed rotor of an axial turbomachine compressor. The rotor comprises a drum supporting a plurality of blade rows. The drum comprises a mounting recess for each row of blades. A number of blades are arranged on a common carrier forming a segment. The latter is fixed to the rotor by insertion in the corresponding recess in the drum. The carrier comprises on its lower face, i.e. opposite the actual blades, a massive rib capable of being inserted into the recess in the drum. The rib comprises a groove on each of its opposite faces. The recess in the drum comprises two leaf springs extending circumferentially in the respective grooves in the recess of the drum. When inserting the carrier common to several blades, the front side of the rib comprises tapered faces surfaces designed to come into contact with the leaves and to slide along the latter so as to push them into their respective grooves against the elastic forces generated by their movement. Once the lateral grooves in the rib are opposite the leaves, then the latter may enter it by virtue of the elastic force they exert. The leaves, once in place, then straddle the corresponding recesses of the blade carrier and the drum, thus ensuring the blades are attached to the rotor. This method of attaching is of interest but has some drawbacks. It requires a significant amount of material in the carrier and the drum, which greatly affects the resulting mass of the engine and, more importantly, greatly increases the centrifugal forces, which limits the diameter and maximum speed of the drum.
U.S. Pat. No. 2,944,326 A discloses a technique for attaching the blades of an axial turbomachine compressor to the rotor. The blades have a platform, reduced in size, whose cross section has a wedge-shaped profile. A groove is formed by coining each side face of the platform. The rotor wall comprises one aperture per blade, the profile of the aperture corresponding to that of the blade platform. Each blade is then inserted into an aperture in the rotor from which it is prevented from exiting in one direction because of the conical or wedge-shaped profile of the platform and of the aperture housing it. Press tools, such as a punch and a die are then used to exert high pressure on the face of the rotor directly adjacent to the edges of the aperture corresponding to the lateral grooves in the platform. The objective of this operation is to push back the material forming the aperture to the inside of the lateral grooves in the platform to ensure its grip, particularly in the direction opposite to that mentioned. The blade is thus held firmly in both directions radially with respect to the rotor. This method of attaching is of interest but has some drawbacks. It requires the rotor to be extremely thick at the point where it is attached to the blades. The principle of mounting the blades with a conical profile platform can only work with a certain thickness of material. This is also true in order to push back the material in a lateral groove. This method of attachment is not suitable for light drums which consist essentially of a thin wall forming the web of the drum.
U.S. Pat. No. 2,685,405 A discloses a bladed rotor of an axial compressor, in which the blades are hollow and in fluid communication with the rotor. Each blade comprises a platform forming a mounting recess. The rotor consists of several sections joined to each other. The mounting of the blades on the rotor is provided by two contiguous rings for each blade row. Each of these two rings has an edge with cut-outs matching the corresponding half of the profile of the mounting recess for the blades. The recesses and the blades are sandwiched between two mounting rings, the latter being mechanically attached to the remainder of the rotor. This type of rotor is designed for the rotor stages to be in fluid communication. As with the previously detailed interpretations, this type of installation requires a great deal of material. Furthermore, it requires the manufacture of numerous components and considerable effort to assemble.